<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>javascript</title>
    <style>
        #main {height: 100%;overflow: hidden;}
        .m_content {width: 200px;float:left;background-color: darkorange}
        .m_rightside {height: 100%;padding-bottom: 10000px;margin-bottom:-10000px;
        background-color: #d9dde1;margin-left: 200px}
    </style>
</head>
<body>
<div id="main">
    <div class></div>
</div>
</body>
</html>